schulz



@et 23, 192s.

W. SCHULZ INTERNAL COMBUSTION ENGINE 4Filed. June 17, A3.926

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Oct. 23,', 1928.

Oct 23, w. SCHULZ Y INTERNAL coNBUsTIoN ENGINE Filed June 17. 1926 s sheets-Sheet 6 FVW@ fmfenor.- W/Ja/z Patented @et 23, 1928.

n is "its i arent WALDEMAR SCHULZ, OF NEU-RUPPIN, GERMANY.

INTERNAL-COMBUSTIO ENGINE.

My invention relates to internal combustion engines of the type in which the air for combustion is compressed to ignition temperature in a plurality of stages, and to a method of operating engines of this two-stroke cycle type.

It isr an object of my invention to perform the compression of the air under more etlicient conditions, and to this end'and in contradistinction to the usual method in which the compression of the air is effected for the major part by the piston of the engine, l effect the first or preliminary compression by a compresser actuated by the engine, and the final compression by the engine piston. The fuel is not Vaporized but only atomized and ignited in atomized condition.

My novel method considerably reduces the load on thel piston and therefore it is not necessary to increase the size of parts notwithstanding the high pressures attained.

ln the drawings, an engine in which my novel method is performed, is illustrated somewhat diagrammatically by way of eX- ample. rl'his engine is particularly adapted to the vpropulsion of vehicles but it is to be understood that l am not limited to this particular field.

Parts that have no bearing on the invention and which are found in any engine, for instance, the crank shaft, the crank case, the timing gear and other accessories, are not shown. f v

Fig. 1 is an elevation, partly in section, of the cylinders of the engine,

Figs. 2 and 3 are sections of cylinders taken at right angles to the partial section in Fig. 1 showing the piston at its upper dead centre and at its l wer dead centre, respectively,

Fig. is a section showing the left-hand half of the cylinder in Fig. 2 on a larger scale.

Fig. 5 is a plan view, seen from below,

Fig. 6 is an end elevation, and

Fig. 7 is a longitudinal section of one of the fuel control cams,

F 1s. S and 9 are diagrams showing means for varying the stroke of the fuel and air control slides, respectively,

Fig. 10 shows the position of the valve 22 by means of which the connection with passages 25 and 21 is effective.

Referring now to the drawings, 1 are the jackets of the cylinders 2, 3 are their pistons, 3 is one of the connecting rods, and 4 are stationary hollow piston rods depending from the cylinder heads and projecting into cylinders (i in the pistons 3. "lhe usual packing rings are provided between the skirts of the pistons 3 and the cylinders 2, and between the hollow piston rods Ll and the cylinders G in the pistons.

Each cylinder is equipped with two lateral valve chests 10 and 10 which extend in parallel to its axis, fuel being supplied to the valve chest 10 from a pipe 15 with a Cock, and compressed air being supplied to the valve chest 10 from a pipe 20. A hollow fuel control slide 11 with a fuel jet 16 is adapted to reciprocate in the fuel chest 10 under the opposite actions of a fuel control cam 13 on a fuel cam shaft 14, and a spring 12, and a siniilar slide 11 is adapted to reciprocate in the cnest 10 under the opposite actions of an air control cam 13 on an air cam shaft 1l', and of a spring 12. The cam shafts 14 and 14 are actuated from the crank shaft by suitable gearing, these parts including the crank shaft being not shown.

Ports 17 and 1S connect the upper and lower ends of the cylinder 2 with the fuel chest 1() and corresponding ports are formed in the cc 1responding ends of the slide 11 at 17 and 18.V A port 19 at the upper end of the cylinder 2 connects its inside with the air chest 10 and a port 19 in the air slide 11 is adapted to register with the port 19. 17 is a port connecting the lower end of the air chest 1U with the air pipe 20, 23 is an exhaust port at the bottom of the cylinder 2, and 2/1 is an exhaust pipe connected with the port 23 at one end and a suction pump, not shown, at the other.

l check valve 5 inthe bottom of each hollow piston rod 4; which is controlled by a spring 7, is adapted to connect a transverse passage 9 at the bottom of each cylinder G with the inside of the corresponding hollow piston rod l when the valve is lifted from its seat at the end of the piston rod against the action of its spring 7. The passage 9 extends as far as the outside of its piston 2 on the side where the fuel chest 10 is arranged in the side wall of the cylinder and is adapted to register with the port 17,

A compressor having two cylinders is indi cated diagrammatically at 25 in Fig. 1 intermediate the two pairs of cylinders 2, 2 at the front and the rear of the engine and is actu ated from the crank shaft by mechanism not shown. ts delivery pipe 26 is connectedto the upper end of each. hollow piston rod 4 and to a reservoir 21, Fig. 9.

The fuel control cams 13 are made with a parallel face 13 and with an inclined face 132 as shown in Figs. 7 and 8, and a handle 14 is operatively connected with the fuel control shaft 14 so as to displace the shaft and to vary the stroke of the fuel slides 11. A similar handle 142 is connected with the air control shaft 14 and a starting cam 13 is arranged adjacent each air control cam 18. By displacing the shaft 14 the cams 18 and 18 are altei'nately placed opposite the air slides 11. Any suitable means, for instance, sectors 142, 144, may be provide-d for fixing the handles 14, 142 in position.

The air reservoir 21 is connected with the pipe 2O by means of a three-way cock 22, Fig. 9, which is adapted to connect alternata ly the air pipe 2O with the reservoir 21 and with atmosphere at 22, and the delivery pipe 26 of the compressor 25 with the reservoir 21.

My novel method is perforn'ied in this en gine. as follows: U

During the downstroke of the piston 3, air from the pipe 26 opens the valve 5 against its spring 7 and enters the c ylinder 6 where on the following upstroke it is compressed. rl`he fuel slide 11'descends under the action of its cam 18 and when the ports 17 and 17', and 18 and 18 register, the compressed air is ejected from the passage 9 into the slide 11 through the ports 17, 17 and the cylinder head through the ports 18, 18, drawing fuel from the jet 16 and projecting the mixture into the cylinder head above the piston where it is ignited by the heat of compression. It will be understood that the piston merely performs the final stage of the compression and the preliminary compression is effected by the compressor 25. The stroke of the slide 11 and consequently the quantity of fuel admitted is regulated by displacing the shaft 14, as described.

Normally, the cock 22 connects the pipe 2O with atmosphere through the extension 22. During the compression and expansion strokes of the engine, the air slide 11, is held in its upper end position by the spring 12 as shown in Fig. 2, the ports 19 and 19 being disconnected. Then the piston has coinpleted its expansion stroke and is at its lower dead centre it lays open the exhaust port 28. At the'same time. the fuel slide 11 disconnects the ports 17, 17 and 18, 18 as its cani 18 allows it to rise under the action of the spring 12. At the same time, the air slide 11 is depressed by its cam 13, causing the ports 19 and 19 to register and making connection between the cylinder head and the air pipe 20. The exhaust gases are drawn from the bottom of the cylinder by the suction pumpat the opposite end of the pipe 24 while at the same time scavenging air is drawn in through the pipe 20, the port 17, the cavity of the air slide 11 and the ports 19, 19. The duration ofthe scavenging period may be regulated by adjusting the cams 18 by the handle 142.

Excess of compressed air from the compressor 25 is delivered to the reservoir 21 by reversing the cock 22 which reversing may be effected by automatic means controlled by the relative pressures in the pipe 26 and the reservoir 21. Such devices are old in the art and are therefore not shown. then thus reversed the cock 22 connects the reservoir 21 with the pipes 26 and 20. The charge of compressed air in the reservoir 2l is utilized for starting the engine. The cam shaft 14 is displaced by the handle 142 so as to place the cams 18 opposite the slides 11 and to render the cams 13 inoperative. Compressed air enters the cylinders through the ports 17, the cavity of the air slide 11 and the ports 19, 19 and is discharged through the port 23.

I claim:

1. An internal combustion engine of the Diesel type in which air for combustion is raised by compression to the temperature of spontaneous fuel ignition, comprising a working cylinder and piston, one part being formed with a chamber forming a counter cylinder and the other' with a portion coacting with the walls of said chamber to function as a counter piston, means for admittingV air successively to said counter cylinder and working cylinder, said air being simultane ously compressed by reciprocation of said working piston, and means forming a bypass connecting said counter cylinder and working cylinder, afuel nozzle terminating in said by-pass, said pistons being so related to the cylinders in which they travel as to provide a superior pressure differential in the counter cylinder, inducing a How in said by-pass towards said working cylinder, the air in said working cylinder being raised only to the combustion pressure while the air in said by-pass is raised to spontaneous ignition pressure.

2. An internal combustion engine as claimed in claim 1, including a slide valve in which said bypass is formed, controlling the admission of fuel to SaidWOrking cylinder.

3. An internal combustion engine as claimed in claim 1, including a slide valve in which said by-pass is formed, controlling admission of fuel to said working cylinder; and a controlling member for said valve for adjustably positioning the latter so that the quantity of fuel mixture to be forced into the cylinder may be regulated according to the required power of consumption.

4. An internal combustion engine as claimed in claim 1, including a scavenging valve sliding in a passage at the side ofisaid cylinder, said valve being arranged to place the interior of the cylinder periodically'in communication with atmosphere. i

5. An internal combustion engine of the Diesel type in which air for combustion is raised by compression to the temperature of spontaneous fuel ignition comprising coacting relatively reoiproeable parts constituting a two-part compressor one of the cylinders of Which functions as the Working 4Cylinder of the internal combustion engine, means for admitting air to the cylinders of said compressor, the latter being` constructed to compress air in the Working cylinder to the Combustion pressure of the fuel and to spontaneous ignition pressure in the other cylinder, means putting said cylinders into communication at the top of the compression stroke of said compressor, and means for admitting; fuel to the air from the higher compression Cylinder in advance of-its admission to the Working cylinder during the said period of communication between said cylinders.

In testimony whereof l have signed thisI specification.

WALDEMAR SCHULZ. 

